The incidence of invasive aspergillosis among solid organ transplant recipients and implications for prophylaxis in lung transplants

BACKGROUND: Invasive aspergillosis (IA) is associated with significant morbidity and mortality in solid organ transplant recipients but data on the incidence rates stratified by type of solid organ are limited. OBJECTIVE: To describe the attack rates and incidence of IA in solid organ transplant recipients, and the impact of universal Aspergillus prophylaxis (aerosolized amphotericin B or oral itraconazole) in lung transplant recipients. PATIENTS: The 2,046 patients who received solid organ transplants at the Cleveland Clinic Foundation from January 1990 through 1999 were studied. METHODS: Cases were ascertained through computerized records of microbiology, cytology, and pathology reports. Definite IA was defined as a positive culture and pathology showing septate hyphae. Probable IA was clinical disease and either a positive culture or histopathology. Disseminated IA was defined as involvement of two or more noncontiguous anatomic sites. RESULTS: We identified 33 cases of IA (28% disseminated) in 2,046 patients (attack rate = 1.6%) for an incidence of 4.8 cases per 1,000 patient-years (33 cases/6,813 pt-years). Both the attack and the incidence rates were significantly higher for lung transplant recipients vs. other transplant recipients: lung 12.8% (24 cases/188 patients) or 40.5 cases/1,000-pt year vs. heart 0.4% (3/686) or 1.4 per 1,000-pt year vs. liver 0.7% (3/439) or 2.1 per 1,000-pt year vs. renal 0.4% (3/733) or 1.2 per 1,000-pt year (P < 0.01). The incidence of IA was highest during the first year after transplantation for all categories, but cases occurred after the first year of transplantation only in lung transplant recipients. The attack rate of IA in lung transplant recipients was significantly lower after institution of routine Aspergillus prophylaxis (4.9% vs. 18.2%, P < 0.05). CONCLUSIONS: The highest incidence and attack rate of invasive aspergillosis among solid organ transplant recipients occurs in lung transplant recipients and supports the routine use of Aspergillus prophylaxis for at least one year after transplantation in this group.